Orthopedic compression plate

ABSTRACT

An orthopedic plate has a first end including a locking screw hole that receives a locking screw and spaced from that hole is a compression housing that extends from the bone-facing side of the plate and which receives a compression screw that forms an angle of from about 10° to about 70° with a longitudinal axis of the plate. In a further embodiment, the plate also includes a second end with a chamfer for insertion of the plate into bone, and in a still further embodiment, the plate is an MTP plate.

CROSS REFERENCE

This Application claims the benefit of priority under 35 U.S.C. §119 ofU.S. Provisional Application Ser. No. 61/463,323, filed on Feb. 15, 2011and U.S. Provisional Application Ser. No. 61/580,680, filed on Dec. 28,2011, herein fully incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to an orthopedic plated which isconfigured to increase compression at a bone interface, in particular tostabilize bones or bone fragments relative to each other such as tocause fusion. Specific embodiments and methods of fixation are presentedfor fixation of the bones of the foot including, for example,stabilization of a fracture, dislocation or reconstruction of adeformity such as use in osteotomies and bunionectomies. The inventionalso applies to fusion procedures in other areas of the body, includingthe wrist or hand.

BACKGROUND OF THE INVENTION

The feet and the hands both include numerous bones and joints thatcooperate together to define quintessential human movement. They aresophisticated, delicate and altogether elegant in function and design.Together the foot and ankle have over 25 bones and 33 joints along withmore than 100 named muscles, tendons, and ligaments and a network ofblood vessels, nerves, all residing beneath a relatively slim coveringof soft tissue and skin. Structurally, the foot has three mainanatomical regions: the forefoot, the midfoot, and the hindfoot. Theseparts work together with the ankle, to provide the body With support,balance, and mobility. A structural flaw or malfunction in any one partcan result in the development of problems, which are manifested in otherareas of the body. The hand forms a cognate to the foot with 27 boneswithin the hand and wrist. There are eight small bones within the wristcalled the carpals, which join with the radius and the ulna to form thewrist joint. The carpals connect with the five metacarpals to form thepalm of the hand, which terminate in the rays (i.e., the thumb andfingers) formed by the phalanges. The three phalanges in each finger areseparated by two joints, called interphalangeal joints (IP joints). Theone closest to the MCP joint (knuckle) is called the proximal IP joint(PIP joint). The joint near the end of the finger is called the distalIP joint (DIP joint). The thumb only has one IP joint between the twothumb phalanges. The IP joints of the digits also work like hinges whenyou bend and straighten your fingers and thumb.

Similarly, the forefoot includes the five toes (which are also known asthe “phalanges”) and their connecting long bones (or “metatarsals”).Several small bones together comprise a phalanx or toe. Four of the fivetoes have three phalanx bones respectively connected by two joints. Thebig toe (or “hallux”) has two phalanx bones distal and proximal with ajoint in between called the interphalangeal joint. The big toearticulates with the head of the first metatarsal at the firstmetatarsophalangeal joint (the “MTP” joint) and there are two tiny,round bones called sesamoids on the plantar side of the metatarsal head.The phalanges are connected to the metatarsals at the ball of the foot.The forefoot balances pressure on the ball of the foot and bears asubstantial amount of the body weight.

The bones of the midfoot from medial to lateral are the 1^(st) through3^(rd) cuneiform, the cuboid, and the crescent shaped navicular boneposterior to the cuneiforms, which also forms a joint with the talusthat forms the basis for the ankle joint at the hinged intersection ofthe tibia, the fibula, and the foot. The five tarsal bones of themidfoot act together form a lateral arch and a longitudinal arch, whichhelp to absorb shock. The plantar fascia (arch ligament) underlays thebones of the midfoot and along with muscles, forms a connection betweenthe forefoot and the hindfoot. The toes and their associated midfootbones form the first through fifth rays beginning with the great toe asthe first ray. The bones which form the palmate portion of the hand are:the scaphoid, the lunate, the triquetrum, the pisiform, the trapezium,the trapezoid, the capitate, and the hamate, which act in concert toallow the opposition of the thumb with each of the fingers and to permitthe uniquely human ability to manipulate objects.

The hindfoot is composed of three joints (subtalar, calcaneocuboid &talonavicular) and links the midfoot to the ankle. The heel bone (or“calcaneus”) projects posteriorly to the talus and forms a lever arm toactivate the hinged action of the foot so as to allow propulsion of theentire body from this joint. The calcaneus is joined to the talus at thesubtalar joint. The mid-foot is often the subject of trauma, such asresults from falls, vehicle, crashes and dropped objects. Theseaccidents often result in severe fractures and/or dislocations. Inaddition, there are several conditions which result from congenitaldeformation or which arise as a result of repeated use type injuries.Surgical intervention that includes surgical sectioning of bone or an“osteotomy” is often used to restructure the bones as a treatment forsuch conditions, for example, the bunionectomy. The present invention islikewise useful for conditions of the hand that result from priortrauma, surgical intervention or defects from birth or that develop withage (such as rheumatoid arthritis).

Examples of some of the other procedures with which the presentinvention could be used include hallus valgus and hallus rigiduscorrections. Other applications which could use the present inventioninclude first and fifth metatarsal chevrons, translational osteotomies,closing wedge osteotomies, pediatric femoral osteotomies, metacarpal andcalcaneal rotational osteotomies, intrarticular osteotomies and hand andwrist realignment osteotomies. Specific surgical techniques arediscussed for the use of an embodiment of the invention designed for usein bunionectomies.

Typical surgical treatment of the foot or hand re-establishes a normalanatomy while the fractured bones mend. In some cases, fusion of a jointmay be necessary, for example, where arthritis arises in a patient dueto use injuries, poor bone or prior unsuccessful surgeries. One currentsurgical treatment of these conditions requires that pins, wires and/orscrews be inserted to stabilize the bones and joints and hold them inplace until healing is complete. For example, a pin or screw may beintroduced medially into the internal cuneiform and through the base ofthe second metatarsal bone. While the use of k-wires, pins, and screwsmay provide acceptable results for younger and more plastic patients,these methods of fixation are not always satisfactory.

SUMMARY OF THE INVENTION

In accordance with the present invention an orthopedic plate is providedthat achieves improved compression through the use of a screw that issituated with its axis obliquely to the spine, of the plate (i.e. to thelongitudinal axis of the plate taken at the opening of the compressionopening of the plate). The screw is received in a housing which includesan opening in the top surface of the plate and a shroud which extendsfrom the bottom surface of the plate so as to define a pocket on thebottom of the plate that captures the screw at a variable orientation.The housing extends through the plate to accommodate the entire diameterof the head of the screw. Thus, the screw head does not project beyondthe top surface of the plate when the screw is fully seated in thehousing. (By “top” it is meant herein the exterior facing surface, whichis opposite the bone-facing surface, of the plate of the plate when theplate is in position on the bone. It is understood that the orientationrelative to the ground is dependent on the orientation of the plate inspace, and therefore that is not relevant in determining what is “top”in this case). The housing also includes ah opening on the bottom of theplate through which the screw extends and which is smaller than thediameter of the screw head so as to capture the screw in the housing.Also the housing is slightly larger than the bottom opening so that theconvexly rounded screw head has some play in the pocket to allow somefreedom of angulation (i.e. about 5 to about 30°, preferably about 10 toabout 20°) of conical or modified conical rotational freedom of thescrew relative to the housing axis (as measured from the groove formedthrough the compression opening.) The angle of the axis of the obliquescrew is from about 10° to about 70°, more specifically about 25° toabout 60° and most specifically about 35° to about 55° degrees to alongitudinal axis of the plate which dissects the compression opening onthe plate (i.e. the “spine of the plate”). A compressive force isapplied to the bone by the plate as the oblique screw is screwed tighterand the screw head compresses into an increased fit with the pocket, andin particular with the pocket bottom opening. This draws the bonesegment into which the compression screw is screwed toward the lockingscrew or screw in the other end of the plate.

In the specific embodiments shown, the plate can include and is limitedto (i.e. “consists essentially of”) a simple tab-like shape with thecompression housing at one slightly elongated rounded end of the plateand a locking screw hole with external threads that mate with ahinternally threaded hole at the other rounded end of the plate where theplate profile or outline does not include other projections, but islimited to a first end and second end, with a first end having thebottom compression pocket with the first end opposing a second end witha second hole including internal locking threads, and the plate outlinedefining an longitudinal axis about which the plate is symmetrical andalong which the compression hole and the locking hole are aligned. Inthe z plane, the plate can include a continuous curve of the same radiusalong the length of the longitudinal axis, i.e. to form a portion of acylinder.

In a second embodiment, of the plate, a more complex and applicationspecific configuration is illustrated as a MTP plate, which is intendedto span the MTP joint. In a first version of the MTP plate of thepresent invention, the plate has (again “consists essentially of”) afirst end with two lateral tabs on either side of a middle tab, and asecond end with two lateral tabs and no intermediate tab. Each of thesetabs is provided with a threaded screw hole that receives a threadedlocking screw. The end with the two tabs, also includes a compressionhousing as previously described that accepts a screw which extendstoward the first end of the plate with its axis at an oblique angle ofabout 5° to about 40°, more preferably about 10° to about 30°, and mostpreferably about 15° to about 25° with respect to the longitudinal axisof the plate. Further, the plate has an angle of up to about 10° (andpreferably about 5°) for dorsiflexion and an angle up to about 10° forvalgus. The bottom surface of the plate is radiused. This allows theplate to be in snug contact with the bone. This plate is also providedin a second version which differs from the first in that the second enddoes include three tabs similar to the first end, an the compressionhousing is located at at an oblique angle of about 5° to about 40°, morepreferably about 10° to about 30°, and most preferably about 15° toabout 25° to the lateral side of the plate and intermediate along thelongitudinal axis to the tabs, and further houses a screw holethat-defines an axis at an angle of about 55°, /−about 15°, preferablyabout 10°, and most preferably about 5° to a line perpendicular to theplate surface at a point along the plate longitudinal axis. Thecompression housing is similar in concept to the previously describedcompression housing, but in this case, has a round footprint describingat least a portion of a circle, and preferably is substantially aportion of a circle, with a leading edge that is linear. Once again, thehousing has an internal recess that houses the compression screw andwhich has a narrowed opening, that is smaller than an associated screwhead so as to capture and retain the screw, but which allow for conicalrotation in the compression housing.

In a third embodiment, the plate is a bunionectormy plate, whichincludes (and which “consists of” or “consists essentially of”) a firstend with symmetrical lateral tabs (i.e. mouse ears) and a second taperedend with a deep chamfer for insertion into bone. The tabs includethreaded locking holes for threaded locking screws. The plate, includesthe compression pocket (described above) and screw spaced from, but atthe same end (that is more or less in the middle of the plate) as thedouble lateral tabs. The pocket receives and captures a rounded headedscrew, which extends obliquely toward the chamfered end of the plate.This plate is planar on the top side and the bottom side, except for theprotruding housing on the bottom side.

The invention also relates to a novel surgical procedure, which is abunionectomy that involves the use of the bunionectomy plate of thepresent invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top perspective view of the orthopedic compression plate inaccordance with the present invention;

FIG. 2 is a top view of the orthopedic plate of FIG. 1;

FIG. 3 is a first side view of the plate shown in FIG. 1;

FIG. 4 is a first cross-sectional view of the plate shown in FIG. 1,taken along line 4-4;

FIG. 5 is a right end view of the plate shown in FIG. 1;

FIG. 6 is a left end view of the plate shown in FIG. 1;

FIG. 7 is a top perspective view of second embodiment of the orthopediccompression plate in accordance with the present invention;

FIG. 8 is a top view of the orthopedic plate of FIG. 7;

FIG. 9 is a bottom view of the orthopedic plate of FIG. 7;

FIG. 10 is aside and bottom perspective view of the plate of FIG. 7;

FIG. 11 is a first side view of the plate shown in FIG. 7;

FIG. 12 is a first cross-sectional view of the plate shown in FIG. 8,taken along line 12-12;

FIG. 13 is a side view taken from the other side of the plate shown inFIG. 7;

FIG. 14 is a second cross-sectional view of the plate shown in FIG. 8,taken along line 12-12 and looking in the opposite direction from FIG.12;

FIG. 15 is a left end view of the plate shown in FIG. 7;

FIG. 16 is a right end view of the plate shown in FIG. 7;

FIG. 17 is top perspective view of a further embodiment of an orthopedicpocket compression plate in accordance with the invention;

FIG. 18 is a first side view of the plate shown in FIG. 17;

FIG. 19 is a top view of the plate shown in FIG. 17;

FIG. 20 is a first cross-sectional view of the plate shown in FIG. 17,taken along line 20-20;

FIG. 21 is a side and bottom perspective view of the plate of FIG. 17;

FIG. 22 is a side view, of the plate of FIG. 17;

FIG. 23 is a bottom view of the plate of FIG. 17;

FIG. 24 is a left end view of the plate of FIG. 17;

FIG. 25 is a right end view of the plate of FIG. 17;

FIG. 26 is a view the plate of FIG. 17 on the first metatarsal afterbunionectomy surgery;

FIG. 27 is a view of the plate and bone shown in FIG. 26 from the topand lateral side of the bone;

FIG. 28 is a view of the bone and plate of FIG. 26 taken from the medialside of the body;

FIG. 29 is a view of the bone and plate of FIG. 26 taken from the bottomside of the bone;

FIG. 30 is a view of the bone and plate of FIG. 26 taken from the topside of the bone;

FIG. 31 is a top view of a second version of the embodiment of theplate: shown in FIG. 7;

FIG. 32 is a first side view of the plate shown in FIG. 31;

FIG. 33 is a cross-section of the plate shown in FIG. 31 taken alongline 33-33;

FIG. 34 is a bottom view of the plate shown in FIG. 31;

FIG. 35 is a cross-section of the plate shown in FIG. 31 taken at line35-35;

FIG. 36 is a top view of a third version of the embodiment of the plateshown in FIG. 7; and

FIG. 37 is a detail in cross section of the plate shown in FIG. 31.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1-6 show a first embodiment of the compression pocket plate of thepresent invention. This embodiment illustrates the compression housingof the present invention used with a universal two ended plate 10 whichcan be used for a variety of applications in which it is desirable toachieve compression for a relatively small area between bones or bonefragments. The plate has a first end 12 having a rounded tab 13 justlarge enough to form a suitable mounting for a threaded locking hole 14,which receives a threaded locking screw 30. As used herein the term“tab” suggests a projection which includes a rounded portion for examplelarge enough to accommodate an opening for a screw hole and contiguousmaterial which holds the rounded projection to the general plate body.The plate also has a second end 18 with an elongated tab 15 thatincludes a compression housing 16. The compression housing 16 includesan opening 20 in the top surface 22 of the plate. The opening 20 isovoid, with a width that wide enough to accept the compression screw 32that is received in the opening 20. The opening 20 angles into the topsurface 22 of the plate 10 so as to form a groove 24 that accommodatesand guides the screw 32 and a mating driver as the screw is screwed intothe bone below the plate. On the bottom surface 23 of the plate 10 thereis a shroud 26, which has a rectangular flat rear surface 27 joined toflat side walls 28. The shroud 26 includes a lower opening 29 which iscircular, and which is large enough to allow the major diameter of thescrew to pass through, but which is smaller than the diameter of therounded portion 34 of the head of the screw 32.

FIGS. 7-16 show a first version of an application specific plate whichis for use in the MTP joint, the junction of the head of the firstmetatarsal and the proximal phalange of the first ray (i.e. the greattoe) at the first metatarsophalangeal joint. The plate used in fixation(i.e. for fusion) of the bones of the first MTP joint, and is thustermed an MTP plate. The plate 110 has a first end 112 which istri-lobed, or has three rounds tabs 113, of just appropriate size toform mounting rings for threaded locking holes 114 which receivethreaded locking screws 130. The tabs are longitudinally offset fromeach other, and angled inward toward the medial axis of the plate toimprove the purchase in the plate, and inhibit backout. The other end118 of the plate 110 includes two laterally and longitudinally offsettabs 115 which are also just of appropriate size to form mounting ringsfor threaded locking holes 114 which receive threaded locking screws130. The second end 118 of the plate includes a compression housingsimilar 116 to that described for the universal plate. The compressionhousing 116 includes an opening 120 in the top surface 122 of the plate.The opening 120 is ovoid, with a Width that wide enough to accept thecompression screw 132 that is received in the opening 120. Thecompression screw is of slightly greater diameter and of greater lengththan the locking screws. The opening 120 angles into the top surface 122of the plate 110 so as to form a groove 124 that accommodates and guidesthe screw 132 and a mating driver as the screw is screwed into the bonebelow the plate. On the bottom surface 123 of the plate 110 there is ashroud 126 which has a rectangular flat rear surface 127 joined to flatside walls 128. The shroud 126 includes a lower opening 129 which iscircular, and which is large enough to allow the major diameter of thescrew to pass through, but which is smaller than the diameter of therounded portion 134 of the head of the screw 132. The end 118 with thetwo tabs 115, also includes a compression housing 126 as previouslydescribed that accepts a screw 132 which extends toward the first end112 of the plate with its axis at an oblique angle of about 5° to about40°, more preferably about 10° to about 30°, and most preferably about15° to about 25° with respect to the longitudinal spine of the plate.Further, the plate has an angle of up to about 10° (and preferably about5°) for dorsiflexion and an angle up to about 10° for valgus. The bottomsurface of the plate is radiused at a constant curve.

A third embodiment of the plate is shown in FIGS. 17-30. In thisversion, the plate is intended for a bunionectomy. The plate 210 has afirst end 212 having symmetrical double rounded tabs 213 (i.e. mouseears) just large enough to form a suitable mounting for threaded lockingholes 214, which receive a threaded locking screws 230. The also has asecond end 218 with an elongated tab 215 that tapers and includes asharp chamfer, suitable for insertion into bone, such as by tamping. Theplate also includes a compression housing 216. The compression housing216 includes an opening 220 in the top surface 222 of the plate. Theopening 220 is ovoid, with a width that wide enough to accept thecompression screw 32 that is received in the opening 220. The opening220 angles into the top surface 222 of the plate 210 so as to form agroove 224 that accommodates and guides the screw 232 and a matingdriver as the screw is screwed into the bone below the plate. On thebottom surface 223 of the plate 210 there is a shroud 226, which has arectangular flat rear surface 227 joined to flat side walls 228. Theshroud 226 includes a lower opening 229 which is circular, and which islarge enough to allow the major diameter of the screw to pass through,but which is smaller than the diameter of the rounded portion 234 of thehead of the screw 232.

FIGS. 31-35 illustrate a second version of the second embodiment, i.e.the MPT plate 310, of the present invention. In this version both thefirst and the second ends 312,318 includes three tabs 313,315 andlocking holes 314 within each tab. The plate 310 continues to have thesame angles for dorsiflexion and for valgus. In the first end, in whichan axis can be defined along the medial axis of the plate to themid-line, and dividing the terminal most screw hole in half, the secondtab hole forms an angle of about 25° to the long axis and the screw holehas an angle of about 21° +/−8°, preferably +/− about 5°, and mostpreferably about 2° to the screw axis of the terminal most hole, whilethe screw hole in the third tab has an angle of about 18°+/−8°,preferably +/− about 5°, and most preferably about 2° to the screw axisof the terminal most hole, with a preferred difference of about 3°. Thegeometry of the opposite end of the plate mirrors the first end, withthe exception that the second end further includes a tab 317 for acompression shroud 316 which extends from the bottom surface of theplate and intermediate to the second tab and has a screw housing thatextends from the bottom of the plate at an angle of about 55° +/− about10°, preferably about 8°, and most preferably about 5° relative to thescrew hole axis of the terminal most screw hole. The housing has acylindrical configuration, which intersects the plate at a linear edge.The housing has a narrowed opening that acts to capture a screw housedin the housing but which allows conical rotation in the housing. Theinside wall of the housing narrows at an angle of 40° relative to theaxis of the housing. The housing 316 has a narrowed opening that acts tocapture a screw housed in the housing but which allows conical rotationin the housing. The inside wall of the housing narrows at an angle of40° relative to the axis of the housing. On the bottom surface 323 ofthe plate 310 there is a shroud 316, which has a rear surface 327 joinedto side walls 328. The shroud 316 includes a lower opening 329 which iscircular, and which is large enough to allow the major diameter of thescrew to pass through, but which is smaller than the diameter of therounded portion 234 of the head of the screw 232.

FIG. 36 illustrates a third version of the second embodiment, i.e. theMPT plate 410, of the present invention, which is a mirror image of theplate shown in FIGS. 31-37. Once again, both the first and the secondends 412,418 includes three tabs and locking holes 414 within each taband t the second end also includes a tab 417 for a compression shroud416 which extends from the bottom surface of the plate. The platecontinues to have the same angles for dorsiflexion and for valgus. Thegeometry of the opposite end of the plate mirrors the first end, withthe exception that the second end further includes a fourth tabintermediate to the second tab and has a screw housing that extends fromthe bottom of the plate at an angle of about 55° +/− about 10°,preferably about 8°, and most preferably about 5° relative to the screwhole axis of the terminal most screw hole. The housing has a cylindricalconfiguration, which intersects the plate at a linear edge.

In one method of causing locking of the screw relative to the plate, thescrew could include external screw threads that mate with internalthreads in the locking screw hole at a pre-selected angle, in someinstances, the screw axis is perpendicular to a tangent at the top ofthe screw hole so that the screw axis angles slightly toward the bottomof the plate. However, other methods of pausing locking could beemployed, such as a variable locking assembly. The screw used in thecompression housing has a rounded rear shoulder (such as a hemisphere,or a torroid), which allows for play in the convexly rounded recess inthe compression housing. The compression is caused when the compressionscrew engages the bone and pulls the plate into that bone, and thelocking screw or screws act on their respective bone segment.

The screws useful with the plate of the present invention areself-starting, self-tapping screws including the option of partial orfull cannulation. The screws include a cutting end having multipleflutes, and preferably 2 or 3 flutes about a conical recess, andpreferably have a rounded end to avoid soft tissue irritation shouldthey break an opposing cortical surface. The screws further include apartial taper of the inner diameter in the proximal end over the firstseveral thread turns, for example over 2-8, and preferably over 3-5turns in order to increase the fatigue life of the screw as well asproviding potential physiological advantages in use. The screws furtherinclude a torque driving recess.

The plate is formed of a biocompatible material, and preferably a metalsuch as surgical grade stainless steel, titanium or a titanium alloy.Preferably, the plate has a thickness of between about 1.0 and 2.0millimeters, more preferably between about 1.2 and 1.5 millimeters, andmost preferably between about 1.25 and 1.40 millimeters. The compressionhousing extends a depth below the bottom surface of the plate from about1.4 to about 3 mm, preferably from about 1.75 to about 2.25 mm, and hasa width of from about 3.5 to about 5.5, preferably from about 4 to about5 mm., and a length of from about 3.0 to about 8.0, mm preferably fromabout 5.0 to about 7.0 mm. The opening in the upper surface of the platefor the compression opening is from about 8 to about 15 mm in width, andfrom about 10 to about 18 mm in length. The lower opening is about 2.5to about 2.9 mm in diameter with a recess width of from about 2.5 toabout 4.5 mm. The locking screw holes include a flat annular recesssurrounding the threaded area that is about 0.4 to about 0.6 mm in.width. The. universal plate (i.e. the tab-like plate) has a length offrom about 35 to about 45 mm, preferably from about 38 to about 42 mm,and the compression screw axis forms an angle of from about 30° to about40° to a longitudinal axis oh the top of the plate. The MTP plate has alength of from about 40 to about 50 mm in length, The compression screwaxis forms an angle of about 22° to about 37° with a longitudinal axistangent to the bottom of the plate at the housing exit. In thebunionectomy plate, the chamfer at the bone insertion end is from about5° to about 15°, preferably from about 8° to about 12°, and the lengthof the chamfer is from about 2 to about 4 mm, preferably from about 2.5to about 3.5 mm and the plate has a total length of from about 175 toabout 225 mm, preferably from about 185 to about 200 mm, with the taper.The axis of the compression screw forms an angle of from about 35° toabout 45° to a longitudinal axis on the bottom of the plate. The plateincludes a continuous outer edge which is defined between the top andthe bottom surface. In addition, the plate 10 can include a smallthrough hole 28 sized to receive a K-wire or other similar guide wire.

During the surgery the joints are first prepped which may includede-articulation between the bones to be fused. The bones are reduced,the plate is located such that all of the screws are aimed into thetargeted bones and away from the joint, and the locking screw(s) isinserted into a pre-drilled pilot hole or holes. A pilot hole is drilledfor the compression screw, and the compression screw is tightened intoposition. The two locking screws are screwed into adjacent cunieforms.The plate is viewed radiographically. The incision is closed per theusual method.

For the bunionectomy in accordance with the invention, the firstmetatarsal joints are first prepped which may include de-articulationbetween the bones to be fused and removal of any bone as part of theosteotomy, and as necessary, the plate is bent to contour to the bonesurface. A pilot hole may be drilled into the bone into which the platewill be inserted. The plate is inserted into the plate recess in a platedriver and secured by tightening the plate upward in the plate holderusing the plate holder having an end that has threads, which mate withthe locking threads of the locking hole in the plate. The plate istamped into the cancellous portion of the bone fragment optionally bytapping the plate driver with a one pound mallet as is necessary toinsert the plate. The plate should be driven until the recess or pocketmakes contact with the anterior portion of the calcaneus bone. An areamay be cleared on the cortical surface of the area of bone that willreceive the section with the locking screws. Once the tapered end of theplate is sunk, a drill guide is mated to the plate drive, and a hole isdrilled for the locking screw. The plate can be held in position usingolive wires (thru the locking holes and into the bone). The plate islocated such that all of the screws are aimed into the targeted bonesand away from the joint, fracture, or bone interface. The olive wire isremoved if used, and a pilot hole is drilled at the end of the platethat includes the first hole and this hole is pinned or screwed. Asecond pilot hole may be drilled for the compression screw at thedesired angle given an optional 15° of conical rotation within thecompression screw hole and a non-locking screw is inserted into thispilot hole and tightened. As the compression screw is tightened in theangled hole, it will drive compression toward the fusion site and thelocking holes. The plate is viewed radiographically, and the softtissues are closed in the usual manner.

The following is a description of a surgical technique for an MTP fusionusing the MTP fusion plate in accordance with the present invention.First, prepare the MTP joint for fusion and choose the desired platefrom the surgical tray. Note, that the plates are pre-contoured toprovide 10° of valgus and 5° of dorsiflexion and can be used on eitherfoot. The plates should, be placed so that the plate's pocket is on themedial side of the foot. For instance, using the Alpha™ plate on theright foot the pocket is on the proximal side of the joint. When used onthe left foot, the pocket of the Alpha™ plate is on the distal side ofthe joint. If necessary, use the bending pliers to contour the plate tothe bone surface. Using a k-wire, placed in the plantar portion of thebones from medial to lateral across the joint, temporarily fix the jointin the desired position. Assemble the template that corresponds to thechosen plate with the countersink guide by snapping the template intothe guide. Lay the template on the bone and orient to the desireposition of the plate. Place two 0.9 mm k-wires. Prepare for the platepocket and inter-fragmentary screw with the provided countersink throughthe template assembly. Insert the countersink until the shoulder of thecountersink hits the guide normal to the plate in the k-wire holes. Withthe k-wires still in place, slide the template off the bone and usingthe wires to help placement, slide the chosen plate over the k-wires sothat the plate's pocket fits within the prepared hole. Select one of afixed locking, non-locking or variable angle locking screw to be used inone of the threaded locking holes that is on the same side of the jointproximally or distally, as the pocket and chose the appropriate drillbit based on the screw selection. Using a color-coded drill guide, drillto the desired depth, determine the screw length using the depth gages,and insert a selected screw into the hole and drive the screw for eachscrew hole. Using the 1.4 mm guide wire tip, insert a 1.4 mm guide wirein to the pocket hole across the MTP joint and ensure that the guide tipis seated within the pocket before inserting the wire. Use thecannulated drill bit to drill for the inter-fragmentary pocket screwover the guide wire. Determine the required screw length over the guidewire using the depth gage and insert the inter-fragmentary screw in thepocket of the plate using the corresponding driver. Before the pocketscrew is completely seated, remove the k-wire used for temporaryfixation and fully tighten the pocket screw. Fill all remaining screwholes and completely tighten all remaining screws. Verify the correctplacement of the plate and screws, replace soft tissue and close theopening.

In the intraosseous version of the present invention, the plate combinesthe bending strength and rotational control of a plate with thecompression generation of an inter-fragmentary screw and also providesthe advantage of allowing the placement of an inter-fragmentary screwthrough a plate, using the plate to lock the construct in place toachieve optimal compression. This plate uses the axis of the pocket todirect the fixation screw into the proximal metatarsal. This indicationspecific plate and accompanying instrumentation will aid in increasingsurgeon accuracy in screw placement. For larger corrections requiringsignificant displacement of the metatarsal head, the set has anintramedullary plate option, to improve the overall construct stability.The custom bone prep instrumentation and the bottom-side pocket create alow profile construct with no exposed screw heads to cause soft-tissueirritation

Below is an example of a surgical technique of the use of theintraosseous plate having a compression shroud in accordance with theinvention.

First, perform a standard medial approach for the first metatarsalphalangeal joint, and then, using a microsagittal saw, remove the medialeminence, on the distal head of the first metatarsal and make a distal,transverse V-shaped osteotomy (i.e. Chevron) or other translational typeosteotomy through the first metatarsal at least 10 mm from the articularsurface. The cut should be made from medial to lateral. Shift the distalhead of the metatarsal laterally until the desired intermetatarsal angleis achieved. If desired, a k-wire may be used to provisionally fix theosteotomy. Once the desired shift is achieved, place the broach againstthe flat, cut surface of the metatarsal head. Taking care as to theplacement of the broach into the metatarsal parallel to the medialborder of the foot, push the tip of the broach into the proximalmetatarsal shaft until the broach contacts the osteotomy site, makingsure to keep the broach parallel to the medial border of the foot. Ifnecessary, a mallet can be used to gently tap the broach into place.Insert the countersink into the ratcheting handle and through the holein the broach. Drill with the countersink until the shoulder on thecountersink hits the top surface of the broach and remove thecountersink. With the broach still in place, use the microsagittal sawto re-sect the residual (overhanging) proximal metatarsal shaft andremove the broach.

Select the intraosseous plate from the surgical tray and cautiouslyinsert the proximal end of the plate into the plate driver and rotatethe driver insert clockwise until the plate rests securely in the drivepocket. Once the plate is attached to the driver, push the sharp end ofthe plate into the slot prepared by the broach. If necessary, a malletcan be used to gently tap the back of the driver until the driver makescontact with the distal-most portion of the osteotomy on the proximalbone. Once the plate is properly positioned, the 1.6 mm drill bit isinserted through the driver insert to drill a hole for the 2.4 mm fixedangle locking screw. After the hole has been drilled, the insert isunscrewed from the plate and the driver and mating insert is removed.The fixed angle locking screw length is determined using the provideddepth gage and the screw is inserted. The 1.6 mm fixed drill guide isselected, threaded into the other distal locking hole that has not beendrilled and a pilot hole of the desired depth is drilled. Both lockingscrews are fully tightened. The pocket drill guide is attached to thedrill guide handle and inserted to the desired depth with the guidefully seated and oriented so that the trajectory of the drill is assteep as possible in order to help prevent skiving of the drill bit offthe inner surface of the lateral cortex. The depth gage is used todetermine the 2.4 mm non-locking screw length; the selected screw isinserted and tightened until sufficient compression across the osteotomyis achieved. The plate and screw placement is verified usingfluoroscopy. Soft tissues are repaired as needed and the incision isclosed as desired.

While in accordance with the patent statutes the best mode and preferredembodiment have been set forth, the scope of the invention is notlimited thereto, but rather by the scope of the attached claims.

1. A plate and screw system which is capable of fixation of bonecomprising a plate and a locking screw and a compression screw, theplate having a top surface opposing a bone facing surface in the zdirection, and extending along a first length along a longitudinal axisand having a first end and a second end, the first end having a terminalportion with a locking hole and the plate including a compression screwhousing spaced apart from the first end and defining a compression screwhole extending at a compression screw angle relative to the longitudinalaxis which angle is not 90°, and the compression screw housing extendingfrom the bone facing surface of the plate.
 2. A plate and screw systemas set forth in claim 1, wherein the compression screw angle is fromabout 10° to about 70° relative to the longitudinal axis in the zdirection.
 3. A plate and screw system as set forth in claim 2, whereinthe compression screw angle is from about 20° to about 60° relative tothe longitudinal axis in the z-direction.
 4. A plate and screw system asset forth in claim 1, wherein the second end of the plate furtherincludes a chamfer for insertion into bone.
 5. A plate and screw systemas set forth in claim 1, wherein the second end of the plate defines atab and the plates defines an outline consisting essentially of thefirst end and the second end.
 6. A plate and screw system as set forthin claim 5, wherein the first end defines a tab which is longitudinallyaligned with the second end so as to provide for bilateral mirrorsymmetry about the longitudinal axis.
 7. A plate and a screw system asset forth in claim 1, wherein the first end has two tabs which includelocking holes.
 8. A plate and a screw system as set forth in claim 7,wherein the first end has three tabs which each include a locking hole,and the second end has two holes which each include a locking hole, andthe compression screw housing is located intermediate the first end andthe second end.
 9. A plate and a screw system as set forth in claim 7,wherein the first end has three tabs which each include a locking holeand the second end has three tabs which each include a locking hole andthe second end further includes a fourth tab which includes thecompression hole.
 10. A plate and screw system as set forth in claim 1,wherein the plate is a MTP plate.
 11. A plate and a screw system as setforth in claim 1, wherein the first end of the plate includes a set ofmouse ears which each include a locking hole and the second end of theplate includes a chamfer for insertion into a bone.
 12. A plate and ascrew system as set forth in claim 11, Wherein the plate top surface isplanar.
 13. A plate and a screw system as set forth in claim 1, whereinthe plate bone facing surface includes a curve in the z direction.
 14. Amethod of fusing bones, comprising: surgically accessing a bone,selecting a plate which has top side and a bone-facing side and a firstend and a second end aligned along a longitudinal axis and the first endincludes a locking hole, and the plate includes a compression housingspaced in the direction of the second end along the longitudinal axis,the compression housing extending from the bone facing side of the plateand defining a screw hole having an axis that forms an angle of fromabout 10° to about 70 relative to the longitudinal axis of the plate,fixing a locking screw in the locking hole; fixing a compression screwin the compression housing to cause compression in the associated bonetoward the locking hole.
 15. A method of fusing bones as set forth inclaim 14, wherein the plate second end includes a chamfer and thechamfer is inserted into bone.
 16. A method of fusing bone as set forthin claim 14, wherein the method involves a surgical procedure which is abunionectomy.